As developments unfold in the size reduction and compactness of data processing systems and with the continuing increase in the density of integrated circuit chips, it is seen that more and more logic circuitry, including computer processors can be built into smaller physical modules. This allows multiple numbers of processors to be implemented where previously only a single or a portion of a single processor was usually resident.
However, the system buses which connect the various elements and parts of a computer system together, that is to say, the buses which connect the processor to the main memory and to the input/output subsystem, cannot necessarily be reduced proportionately in physical size in the manner by which the processors and memories are reduced in size.
Since it is necessary for multiple processors to share the various system resources, some control must be provided for bus-sharing. This disclosure presents a system for providing a very simple and very low-cost arbitration circuit system or "Arbiter".